Electron micrographs of S. parasanguinis bacteria. S. parasanguinis bacteria, L64R (A), P65R (B), I66N (C), L67T (D) mutant variants and wild type FW213 (E) were placed on grids, and negatively stained with 2% phosphotungstic acid pH7.0 and visualized by electron microscopy. White arrows point to the short fimbriae. Black arrows point to the long fimbriae. Scale bar = 100 nm.